Fifty years after her death, Sylvia Plath's writing and the story of her life, when taken together, provide the perfect medium on to which commentators can project their own private needs and fantasies. So many people think they own her; and Lyn Gardner, in her review of my production of Plath's only play, Three Women, shows that she is no exception (Plath's rawness gets lost in tinkling piano music, 9 January).

"What we are offered," she complains, "is tinkling piano music, mournful mood lighting, an innocuous pale setting, as well as three perfectly good but indisputably ladylike performances that capture none of the wounded redness of Plath's poetry, and do her the disservice of making her sound bleached and somewhat prissy".

So, now we know. Gardner wants "rawness" and "wounded redness" from her Plath. I guess anything short of that would seem pale, innocuous, bleached, ladylike and prissy. I wonder whether Gardner simply has narrow ideas of how and what a woman should be.

As for the music, it's by Schnittke, widely regarded as one of the 20th century's greatest composers. Most of it is from his Little Piano Pieces, written for children (which is why I chose it). His music is not easy for everyone to like, but to call Schnittke "tinkling" is philistine and reductive. It's a bit like calling Shakespeare "wordy" or Pinter "slow". It reminds me of the old joke about modern art: "Which way up does it go?"

Gardner worries that my production "never finds a way to give the internal a physical reality" - apparently believing, like the many proponents of so-called "physical theatre", that this can only be done by moving the body. Plath has already managed it with her extraordinarily physical language and imagery.

The muscularity of this text eclipses any merely corporeal physicality. What could possibly be added that would not distract attention from it or, worse, misrepresent it and risk the gross hubris of suggesting that we could say it better? Gardner says: "Plath's poetry, like most babies, is more robust than it appears - and won't break if treated with a little less reverence." It is not reverence but respect and trust.

We live in an age when directors feel they have to justify themselves by "interpreting" plays to the nth degree, to avoid the allegedly catastrophic accusation that their work is "solid". The writer is the tool of such a director, their work to be chopped, changed and exploited to fulfil her "vision". The actor too is in danger of total exclusion from participating in the creative process - of finally being reduced to Gordon Craig's über-marionette. The theatre director as Jesus in the wilderness? God preserve us from the director's "vision"!

This production is intended as a deliberate antidote to this hypertrophied overdirecting. I just wanted to leave Sylvia alone to speak for herself. This is something so many people, including Gardner apparently, cannot contemplate - and that is the great "disservice" that continues to be done to Plath.

• Robert Shaw is the artistic director of Inside Intelligence, a theatre company specialising in new writing and contemporary music theatre robert@inside-intelligence.org.uk